look inside that post -> https://www.vogons.org/viewtopic.php?f= ... yl#p451252"(Edit: in some games it's also common to lock and access the depth buffer by the CPU to check if something is in occlusion, like the sun for a lensflare effect. The best practical example for this is game Pyl (Glide) which locks the depth buffer multiple times during a single frame to see if the environmental light sources are occluded and decide to render or not their aura. Without partial readback that game is unplayably slow.)"

Can it be discarded, so we turn of light auras in Pyl, and disallow to manipulate so mach with depth buffer, so it be graphicaly worse but run in full speed?

Discarding depth reads would not give you 60fps, half of the resources are consumed by DOSBox and that's not something you can skip.

For nGlide part, you can use one of wrapper's releases that didn't support depth reading (nGlide 0.98 and older), but I don't think playing with invisible enemies will be fun (not only special effects rely on these reads).

i can run game in glide on ntvdm by using glidos, i see intro movies, logos, menu, everything is ok, keyboard clicks ok, only mouse, when i click any mouse button it throw me to desktop without any warnings /errors.

is there any chance you can investigate it to fix?

When game on Software mode everything works perfect.

you can replace glide2x.dll shipped with glidos by glide2x.dll from nGlide, it gives speed, and more resolutions,/.